Nutrient neutral development

Development in areas with nutrient-rich water must mitigate its effects and provide a nutrient-neutral environment.  

Evidence has shown that at some designated international nature conservation sites in the New Forest, there are high levels of nutrients in the water environment, specifically nitrates in Solent catchments and phosphates in the Avon catchment.  The extent of nutrient enrichment causes an excessive growth of plants and algae, known as eutrophication, which reduces the oxygen content in water. This process makes it more difficult for aquatic insects or fish to survive, in turn removing a food source from the food cycle for protected species such as wading birds and salmon.

As housing and overnight accommodation contribute to increased discharges of nutrients, a significant effect from such development on international nature conservation sites cannot be ruled out.  Therefore, an avoidance and mitigation package will be needed in order for us to lawfully grant any planning permission. This is in accordance with The Conservation of Habitats and Species Regulations 2017.

The avoidance and mitigation package would take the form of a financial contribution. The contribution is paid to us by the developer, so that we can implement the package once it has been agreed.

Affected areas

Following recent case law, residential development and other schemes providing overnight accommodation will need to achieve 'nutrient neutrality'.

The Waste Water Treatment Areas Map shows the areas within New Forest that are required to achieve nitrate neutrality. If your development is within this area, it is important you follow the requirements.

You can download a map below showing the waste water areas.

Icon for pdf Waste water treatment areas map [622.0KB]


Our adopted position statement on nutrient neutral development can be seen below. 

Icon for pdf Position statement on nutrient neutral development [277.73KB]

This highlights developments that are expected to provide avoidance and mitigation on-site, thus resulting in a nutrient-neutral development. Whilst the position statement refers to nitrates in the Solent, the same principles apply to phosphates in the River Avon.

It also sets out that, for any other applicable developments, the exact scale of avoidance and mitigation packages is not yet known.

As part of the information needed to determine relevant planning applications, a European Site avoidance and mitigation checklist will be required. You can download this document below.

Icon for pdf European site avoidance and mitigation checklist [211.38KB]

Achieving nutrient neutrality

Links to the latest documents on nitrate neutrality in the Solent can be downloaded below

Icon for pdf Solent Nutrients June 2020 [2.41MB]

Icon for pdf Solent Nutrient Advice - Non-Technical Summary [586.55KB]

Icon for zip Nitrogen Budget Calculator [46.39KB]

Dwelling occupancy rates in NFDC

Paragraphs 4.18 - 4.19 of the NE Guidance v5 includes the following statements:

  • Natural England recommends that, as a starting point, local planning authorities should consider using the average national occupancy rate of 2.4

  • Competent authorities may choose to adopt bespoke calculations tailored to the area or scheme

  • Calculations for occupancy rates will need to be consistent with others used in relation to the scheme (e.g. for calculating open space requirements), unless there is a clear justification for them to differ.

For residential planning applications in the NFDC area the following occupancy rates will be applied, consistent with the approach for mitigating the recreational impacts of new housing on the New Forest European sites.

Dwelling sizeOccupancy per unit
Studio or 1 bed1.4
2 bed2.1
3 bed3
4+ bed3.75


The unspecified dwelling size assumes a housing mix compliant with 6.1 of Policy HOU1 in the Local Plan 2016 - 2036 Part One: Planning Strategy

For outline planning permissions, at detailed application stage we will require that the nutrient budget for the site be recalculated for the actual dwelling mix and layout. Depending on the final unit mix the number of dwellings that can be accommodated may change from the figure in the outline permission.

Other forms of overnight accommodation

Units of visitor or institutional accommodation, or other proposals that include overnight stays including campgrounds, will be calculated on a dwelling-equivalent basis.

As a starting point the occupancy rate for a studio/1-bed dwelling will be applied to a hotel, guesthouse, care home 'room' or a campsite pitch. Relevant and robust evidence on rates of occupancy, including seasonal variations or periods of closure, will be taken into account.

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